Workspace symbols should not affect local diagnostics and jump to definition

[lionel-]

Diagnostics for defined symbols currently use workspace symbols as a source of definitions. This causes definitions in a file to silence "undefined symbol" diagnostics in another file:

# file1.R
foo <- 1


# file2.R
foo # No diagnostic

RStudio is much less liberal. It requires that you source() a script to populate symbols explictly. For instance:

# file2.R
source("file1.R")
foo # Correctly defined

These features should behave more like "document symbols" than "workspace symbols":

• Diagnostics for undefined symbols
• Go to definition

Ideally we'd populate the definitions statically if the sourced file has a static file path. In the meantime we can rely on the dynamic search path, which is what RStudio does as well.